The present invention relates generally to a welding device for pressure welding abutting ends of a pair of workpieces constructed of a pressure weldable metal and, in particular, to a welding device which is adapted to be hand-held by the operator and can accommodate welding dies for welding wires of various sizes.
It is well known that certain metals or alloys can be welded together without heat by utilizing what is known as a cold pressure welding process. Such a welding process is particularly suited to welding together butted ends of a pair of rods, wires, strips, plates or other similar members consisting of aluminum, copper or other cold weldable metals or alloys. Basically, by applying sufficient pressure to the butted ends or surfaces of the members to be welded, the metal of both members will "flow" together and thereby securely weld the members together.
In certain instances, particularly when cold pressure welding relatively small diameter wires or narrow strips, it is desirable to utilize what is known as a "multiple upset technique". With this welding technique, a specially designed die assembly is utilized. The die assembly includes a first and second pair of dies wherein the dies of each pair are relatively moveable toward and away from the other between a released position and a wire gripping position. Further, the pairs of dies are also relatively moveable toward and away from each other between a normal open position and a welding position. The multiple upset welding technique involves a repeated upsetting process wherein the dies undergo the above relative movements through several cycles. A more detailed discussion of the multiple upset pressure welding technique can be found in U.S. Pat. Nos. 3,106,013 and 3,309,766, both issued to W. J. Rozmus.